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Help with 747-400!

PostPosted: Tue Dec 14, 2010 11:58 pm
by Jamie C.
Ok, I've been flying a 747-400 for my VA, just started today cause we got our first one. But it seems I can't climb past FL280. When I do, no matter my speed or anything, the nose goes up dramatically and I fall out of the sky. I've been trying to climb to FL350 at 310 kts. My engines work fine and my airplane seems to be in working order idk what going on. Oh, and they are default planes.

Re: Help with 747-400!

PostPosted: Wed Dec 15, 2010 7:21 am
by Malbec
Hiya

I am a noob when it comes to 747's however, i took one from Bangkok to Hong Kong over the weekend. No reason for the location it was just that i wanted to see the difference between the 747 and the 737 i have been playing about with.

I do not know how you fly but as a noob i set up my autopilot while taxiing and kick it it when i gear up.

I tend to just leave speed to 250kt until i reach over 18,000 and then i gradually speed up after turning on the Mach speed. What i mean by gradually is that i just notch up the speed in increments of 5 and just before it matches the setting i continue again. No real reason for this it just gives me something o do while on auto pilot if i am not setting a heading etc :D

Any way, for my first flight i got her up to FL320 with no issues at all but as i said i do have auto on, my joystick not great for manual.

Now i did save on the start of my decent and i am glad i did because i had the opposite problem to you i got to FL50 and was trying to slow down using the spoilers and nose went up and splash in the sea lol ::). I have learnt it may of been a combination of to much spoiler, turning to line up the run way, and flaps. Or trying for 180 is just to slow for a 747, i dunno. But i did have it saved and did it again but a bit more gently on the decent and found the middle of the runway.

I have waffled on a bit, but my advise, albeit probably not worth it, is keep trying but save at say 18,000 so if it does go pear shaped you can load right back in and tweak something different.

I had a similar problem with concorde but i was to keen and just whacked the mach meter up lol.

Enjoy the 747 she is a beauty when u hit the middle of the runway  :)

Re: Help with 747-400!

PostPosted: Wed Dec 15, 2010 7:30 am
by EVVFCX
Hi,

I'll have a go this evening UK time but on manual to see what happens, trim range should be same as auto

Steve.
PS real world speed is higher

Re: Help with 747-400!

PostPosted: Wed Dec 15, 2010 7:59 am
by Brett_Henderson
During your flight-planning, determine how much fuel you need to carry (a very involved process all by itself).. then per the passenger/cargo load, calculate your gross takeoff weight, and plan your climb accordingly.

A fully loaded 747 cannot just climb to cruise altitude.. you might have to level off periodically and burn off fuel, so that you can continue the climb.

Using a set, indicated airspeed will get you into trouble too (especially an airspeed well above any optimal climb airspeed).. the difference between indcated and true airspeed widens with altitude (and why mach-numbers are used)..

Re: Help with 747-400!

PostPosted: Wed Dec 15, 2010 11:48 am
by dave3cu
Jamie,

Sounds like an excessive climb rate is causing a stall. What is your initial Vert. Spd. setting, and are you reducing it as you climb?

While the 747 can initially climb in excess of 2500 fpm, it can't maintain that climb rate at higher altitudes due to thinner air=less available lift. If the auto-pilot can't maintain an excessive Vert. Spd it will contuinue to trim 'nose up' and eventually stall.

This document-Aircraft Information-Boeing 747-should be usefull.  Using the climb rates and speeds listed should get you to altitude.

Dave

Re: Help with 747-400!

PostPosted: Wed Dec 15, 2010 12:10 pm
by Jamie C.
I started climbing from the runway at 2000fpm tehn when I got to around 17000 I pulled it down to 18000fpm. Also I have the flight sim set so it show my true airspeed. I'll try what that guide says for climbing and go at a smaller angle above 16000

Re: Help with 747-400!

PostPosted: Wed Dec 15, 2010 12:47 pm
by Jamie C.
Thanks for the help guys, I thought I could do 1500fpm-1800fpm for my whole climb. Thanks for the info.  :)

Re: Help with 747-400!

PostPosted: Wed Dec 15, 2010 2:18 pm
by dave3cu
Glad you got it sorted...

Tried your original set up.... 310TAS (true airspeed) and 1800fpm. Like you, I stalled (at 29000).

Re: Help with 747-400!

PostPosted: Wed Dec 15, 2010 8:23 pm
by Jamie C.
Dave could you find me another thing like that except for the 747-800F? Thanks

Jamie

Re: Help with 747-400!

PostPosted: Wed Dec 15, 2010 9:20 pm
by DaveSims
I started climbing from the runway at 2000fpm tehn when I got to around 17000 I pulled it down to 18000fpm. Also I have the flight sim set so it show my true airspeed. I'll try what that guide says for climbing and go at a smaller angle above 16000


That is exactly your problem.  Set your flightsim up to use indicated airspeed, as you would have in real life.  What is happening is while your true airspeed is 310 kts, at that altitude your indicated airspeed is less than 200, and you are stalling. 

Re: Help with 747-400!

PostPosted: Wed Dec 15, 2010 9:25 pm
by Jamie C.
WOW I'm an idiot, lol thanks for the help Dave.  :)

Re: Help with 747-400!

PostPosted: Thu Dec 16, 2010 8:28 pm
by reachva
Once I pass transition altitude on any jet, I usually drop the climb rate to 800 feet/minute and keep a close eye on my indicated air speed and my ground speed.

Re: Help with 747-400!

PostPosted: Thu Dec 16, 2010 10:27 pm
by usapatriot
I climb at whatever climb rate will give me at least 250 kias under 10,000 feet, then I continue to climb at whatever rate will give me between 280-250 kias.

I like to climb fast, usually at 6,000FPM until about 15,000 feet then lower to keep my airspeed past 250 kias.

Re: Help with 747-400!

PostPosted: Fri Dec 17, 2010 9:18 am
by dave3cu
....I like to climb fast, usually at 6,000FPM until about 15,000 feet.......


I'm sure that will excite the passengers

Re: Help with 747-400!

PostPosted: Fri Dec 17, 2010 10:36 am
by usapatriot
Rollercoaster time! The 737-800 is quite adept at climbing fast, even with a fuel passenger and fuel load!

Speaking of which, what are the usual climb rates for commercial airliners?